1. Field of the Invention
The present invention relates to mechanical seals which include a split seal ring which is split into at least two segments of circular arc. There are two types of such a mechanical seal; namely, an outside seal and an inside seal. In both types of such a mechanical seal, the split seal ring has a tapered face. And the split seal ring consisting of the circular arcs is fastened by a fastening ring which presses the tapered face toward an axial direction.
Since the tapered face converts the pressing force in an axial direction to the force in an oblique direction toward the center line of the rotary shaft to fasten the split seal ring, the fastening force is not even, and such force exerts a strain on the sealing face.
It is difficult precisely to form the tapered face, and the incorrect formed tapered face causes strain on the sealing face as well. Furthermore it takes a long time to set the fastening ring precisely on the split ring.
Since conventional mechanical seals need a bolt or the like to secure the fastening ring on the split ring, it is difficult to form the rotary ring in such a split ring.